[WIP] Add builds for iOS

[imWildCat]

According the gn args listed at https://v8.dev/docs/cross-compile-ios, I added required configurations in build.rs.

In addition to these targets, I plan to add support for Mac Catalyst in follow-up PRs:

$ rustc +nightly --print target-list | grep macabi
aarch64-apple-ios-macabi
x86_64-apple-ios-macabi

Can we use v8 on iOS?

TLDR: Yes.

Apple only limits HTML and JavaScript engine for browser apps:

2.5.6 Apps that browse the web must use the appropriate WebKit framework and WebKit Javascript. https://developer.apple.com/app-store/review/guidelines/#minimum-functionality

There're existing cases for non JavaScript core use cases including Hermes, V8 in NativeScript.

[CLAassistant]

All committers have signed the CLA.

[littledivy]

You might also have to make some modifications in build.rs (gn args, etc)

[imWildCat]

Hi @littledivy, could you approve the GH Actions to be run in this PR? Thanks in advance!

[littledivy]

Closing because stale. Feel free to open if you're still working on it.